Process for forming and analyzing signalling messages by storing signalling messages into a buffer store and entering information elements basis into an auxiliary address store

ABSTRACT

In the initial analysis or forming of a signalling message (sm) having a message header (MK) and information elements (IE) appended thereto (for example according to CCITT recommendation Q.93B), the signalling message (sm) is buffer-stored in a buffer store ZSP to information items (ti, ki) defining the information element type and the initial addresses (sia, csia) of the information element-specific information items stored in the buffer store ZSP are entered using of an address generation routine (AGR) into an auxiliary address store (HAS). An indicative information item (hi) is transmitted to the further processing routines (WR), indicating the existence of an auxiliary address store (HAS). The buffer-stored information items (ti, csi, si) of the signalling message (sm&#39;) can be retrieved using a retrieve routine (ABR) and the auxiliary address store (HAS) by the further processing routines (WR). The process makes it possible to retrieve the buffer-stored information items (ti, csi, si) of the information elements (IE) of a signalling message (sm) to be analyzed or of a generated signalling message (sm) with rapid access, either repeatedly or, in particular, only partially.

BACKGROUND OF INVENTION

The invention relates to a process for forming and analyzing signallingmessages in a program-controlled communication device, the signallingmessages having message header information items and informationelements appended thereto, comprising octet-oriented and informationelement-specific information items.

Signalling messages structured in this way are provided in particular inthe case of the signalling protocols Q.931 and Q.93B standardized by theCCITT (Comitee Consultative International Telefonique e Telegrafique).In CCITT recommendation Q.931, the signalling protocol for the thirdprotocol layer of an ISDN (Integrated Services Digital Network) basicaccess is defined. In analogy to this, the signalling protocol for abroadband ISDN basic access is standardized in CCITT recommendationQ.93B. Furthermore, for the signalling in communication networks actingon the basis of the asynchronous transfer mode, a signalling protocolstructured in the same way is provided. In the case of these signallingprotocols, each of the individual signalling messages is formed by asignalling message header and information elements appended thereto. Thesignalling message header has at least one protocol discriminator,indicating the signalling protocol used, a connection referenceinformation item, serving to identify the respective connection in thelocal network, and a type information item, defining the type of thesignalling message. Specified in the appended information item theactual signalling information elements are for the respective type of asignalling message. Each of these information elements is formed by atype information item, indicating the type of information element, alength information item, indicating the number of octets of thefollowing signalling information items--only in the case of CCITTrecommendation Q.93B--and by the appended signalling information items.According to the above-specified CCITT recommendations, both thesignalling messages and the information elements are structured in anoctet-based or byte-based manner. The information items contained in themessage header and the information items to be inserted in the appendedinformation elements are passed on during analysis or generation to theswitching routines further processing the signalling messages or aretaken over by said routines for forming a signalling message.

SUMMARY OF INVENTION

The object on which the invention is based is to design a process foranalyzing and forming signalling messages explained at the beginning insuch a way that the information items contained in the signallingmessages to be analyzed or formed can be taken over by the switchingroutines in a communication device in a partial and time-independentmanner.

In general terms the present invention is a process for forming andanalyzing signalling messages in a program-controlled communicationdevice. The signalling messages have a message header and informationelements appended thereto, defining the information element type andcomprising information element-specific information items. For eachsignalling message to be analyzed or formed for the first time, there isset up a buffer sore for storing the signalling message, and anauxiliary address store for storing the buffer store addresses. Using anaddress generation routine, the information element type and the initialaddresses of the information element-specific information itemsbuffer-stored in the buffer store are defined and entered on aninformation element basis into the auxiliary address store. Theexistence of an auxiliary address store is indicated to furtherprocessing routines of the communication device by transmitting anindicative information item.

It is to be regarded as an important aspect of the process according tothe invention that, when forming or analyzing each signalling messagefor the first time, there is set up a buffer store, storing thesignalling message, and an auxiliary address store, into which theinformation items defining the information element type and the initialaddresses of the information element-specific information items storedin the buffer store are entered in an information element-structuredform with the aid of an address generation routine. The existence of anauxiliary address store is indicated to the further processingroutines--in particular the switching routines--by transmitting anindicative information item. The further processing routines retrievethe entered information items with the aid of an enquiry routine and theauxiliary address store. In this case, the information items definingthe information element type is checked for the information element typebeing sought and, after detecting the information element type beingsought, the information element-specific information items are retrievedfrom the buffer store with the aid of the subsequent initial addresses.By this measure, the buffer-stored information items of signallingmessages, in particular for multiple connection controllers with shortaccess times, can be retrieved as often as desired by the relevantfurther processing routines. The short access times are advantageouslyachieved by using not the type information items of the buffer-storedsignalling message but the type information items entered in theauxiliary address store for checking for the information element typebeing sought or to be selected. When forming signalling messages,further information element routines can be employed to form informationelements or information element information items, whose informationitems defining the information element type and the initial addresses ofthe information element-specific information items are entered with theaid of the address generation routine into further information elementstores of the auxiliary address store. It is achieved by this measurethat signalling messages and the auxiliary address store can be expandedwith the aid of further information element routines.

In the signalling messages, the information items defining the type ofthe respective information element are represented by a type informationitem and the information element-specific information items arerepresented by signalling information items. Into the auxiliary addressstore there are entered on an information element basis the initialaddresses of the signalling information items contained in thesignalling messages and stored in the buffer store and the typeinformation item indicating the type of the respective informationelement, and also a linking information item. It is indicated by thislinking information item whether this information element represents thelast of the current type of information elements or whether at least onefurther information element of the same type follows. The linkinginformation item can be employed when there are a number of informationelements of the same type to define the first information element andthe sequence of the following information elements of the same type orto retrieve them in a corresponding sequence. The storing of thesignalling messages to be analyzed or which have been formed in a bufferstore and the setting up of an auxiliary address store, and also theentering of the information items defining the information element typeand of the initial addresses of the information element-specificinformation items for each signalling message makes possible a selectiveand, in particular, repeated retrieval of the information contents ofthe buffer-stored information elements. By this repeated retrieval ofthe same information element-specific information items, the forming ofvoluminous communication device-internal signalling messages is avoided.In addition, the original signalling message is retained unchanged inthe buffer store, for example for an acknowledgement transmission inreturn directions.

According to CCITT recommendations Q.931 and Q.93B, a code recordinformation item can be inserted into an information element. Accordingto an advantageous development of the process according to theinvention, the initial address of the code record information itemstored in the buffer store can be inserted into a code record store areaof the respective information element store. The message record of asignalling protocol which is currently being used is defined by thiscode record information item, for example the message record for privatebranch exchanges.

Before a further processing of the signalling message entered in thebuffer store this message can be checked with regard to its signallingprotocol conformity. This is achieved particularly advantageously bythere being stored in a test store structure for each type of signallingmessage and the information element contained therein signallingprotocol-conformal signalling protocol information items according tothe currently provided signalling protocol. Following entry of theinformation items defining the information element type and of theinitial addresses of the buffer-stored signalling information items intothe auxiliary address store by comparing the informationelement-specific information items and the information items definingthe information element type on an information element basis with theprotocol information items of the test store structure with the aid ofthe auxiliary address store and a checking routine, and by enteringerror information items into an error indication store if the signallingmessages do not conform to the protocol or are incomplete. By theevaluation of these error information items, it is decided to whatextent the respective signalling message has to be rejected, amended orsupplemented.

For the setting up, i.e. loading and clearing of a corresponding storearea for an auxiliary address store and of a buffer store, it isparticularly advantageous to provide a setting-up and clearing routine.By providing such a setting-up and clearing routine, an auxiliaryaddress store and buffer store can be set up as desired before use and,in particular, storing can be performed in any desired time period afterthe occurrence of a signalling message. This makes possible in aparticularly advantageous way capabilities for post-processing theseinformation items, for example in the case of multiple connections.Particularly advantageously, the above-explained buffer store and theauxiliary address store and also the setting-up and clearing routine arerealized in a communication device--in particular a communicationprivate branch exchange--by an object in an object-oriented programstructure.

With the aid of a message header routine, the message header informationitems explained at the beginning during forming and analyzing of asignalling message and the error information items can be controlled atany desired points in time, i.e. in the case of a signalling message tobe analyzed, they are separately processed, such as for examplebuffer-stored, evaluated and then modified.

BRIEF DESCRIPTION OF THE DRAWINGS

The features of the present invention which are believed to be novel,are set forth with particularity in the appended claims. The invention,together with further objects and advantages, may best be understood byreference to the following description taken in conjunction with theaccompanying drawings, in the several Figures of which like referencenumerals identify like elements, and in which:

FIG. 1 shows a communication device realizing the process according tothe invention and

FIG. 2 shows a buffer store according to the invention and an auxiliaryaddress store for a signalling message to be formed and a signallingmessage to be analyzed, and also the routines provided for this purpose.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

FIG. 1 shows a communication device K, in which there is arranged acontrol device MP controlling and monitoring the communication device K.The communication device K may represent, for example, a communicationprivate branch exchange or a communication terminal. The control deviceMP is realized, for example, by a commercially available microprocessorsystem. This control device MP is connected via a local bus system LB,formed by, for example, control, address and data lines--not shown --,to a random-access memory RAM and a read-only memory ROM. In theread-only memory ROM there are stored the programmed routines requiredfor carrying out the process according to the invention and the teststore structure PST required for the signalling protocol conformitytesting. The required routines represent an analysis or a generationroutine AR, BR, an address generation routine AGR, information elementroutines IR1 . . . IR, a checking routine UR, a setting-up and clearingroutine ELR and a message header routine MKR. In the test storestructure PST there are stored protocol information items pi on asignalling message-individual basis (sm1 . . . n).

In the random-access memory RAM, buffer stores ZSP and auxiliary addressstores HAS, including assigned error indication stores FAS, aretemporarily set up with the aid of the setting-up and clearing routineELR.

The central controller MP is connected via a further, for examplePCM-oriented, internal bus system PCM to a connector unit AE. Thisconnector unit AE is employed to perform the physical and proceduraladaptations to a subscriber line ASL, which is routed for example eitherto a communication terminal or to a communication private branchexchange. The signalling messages sim transmitted via the subscriberline ASL pass after a physical adaptation as internal signallingmessages sm to the central control device MP or are transmitted by thelatter via the connector unit AE to the subscriber line ASL. For theexemplary embodiment, let it be assumed that signalling messages smaccording to the signalling protocol of CCITT recommendation Q.931 areto be transmitted or formed. According to this signalling protocol, thesignalling information items sm are to be transmitted in the thirdprotocol layer of a total of seven protocol layers standardized by theOSI. The first two protocol layers, i.e. the transmission layereffecting the bit transmission, and the saving layer saving thetransmission, are realized by the connector unit AE. The signallinginformation items inserted into the third protocol layer effect theswitching of the messages to be transmitted in, for example, acommunication private branch exchange. In CCITT recommendation Q.931,the structure of the signalling messages sm required for this and alsothe insertable signalling information items are defined.

FIG. 2 shows for a signalling message sm' to be analyzed and asignalling message sm" to be formed in each case a buffer store ZSP',ZSP", including a signalling message sm' to be analyzed and a signallingmessage sm" to be formed, and also an auxiliary address store HAS. Asignalling message sm', sm" is formed by a message header MK and byinformation elements IE1 . . . n appended thereto. The sequence of theappended information elements IE1 . . . n is arbitrary. For theexemplary embodiment, let there be assumed a signalling message sm' tobe analyzed such as is shown in FIG. 2.

With the aid of a setting-up and clearing routine ELR, activated by ananalysis routine AR represented by dash-dotted lines, a buffer store ZSPand an auxiliary address store HAS are set up in the main memory ROM ofthe communication device K after detecting a signalling message sm' tobe analyzed. This means that a store location made to be appropriate forthe number of information elements IE1 . . . n present in the signallingmessage sm' is occupied and made known to the address generation routineAGR or the analysis routine AR. After storing the signalling message sm'in the buffer store ZSP', the message header information mki inserted inthe message header MK is sent for the purposes of further processing orevaluation to the relevant further processing routines WR with the aidof a message header routine MKR initiated by the analysis routine AR.The message header information items mki contain a protocoldiscriminator, indicating the signalling protocol used--in the exemplaryembodiment for example the signalling protocol according to CCITTrecommendation Q.931--a connection reference information item, servingto identify the respective connection in the local network, and a typeinformation item, defining the type of the signalling message--forexample a connection setup message.

Subsequently, with the aid of the address generation routine AGR, theinformation items ti, defining the information element type, and theinitial addresses a of the information element-specific informationitems csi, si are entered on an information element basis into theauxiliary address store HAS, i.e. are stored there. Specificallyconcerned here are a type information item indicating the type of therespective information element IE1 . . . n, initial addresses sia ofinformation element-specific signalling information items si and a coderecord information item csia indicating the currently applicable messagerecord--for example a message record for private branch exchanges. Inaddition, a linking information item ki, defining the linking of theinformation elements IE1 . . . n, is formed by the address generationroutine AGR and is entered into the auxiliary address store HAS.

For the entry of the above-explained information items ti, ki, definingthe information elements IE1 . . . n, and the initial addresses sia,csia, the signalling information items csi and the code recordinformation items si, each information element IE1 . . . n is assignedan information element store IES. Each of the information element storesIES has

for the linking information items ki, a linking store area KSB,

for the type information items ti, a type store area TSB,

for the initial address csia of the code record information items csistored in the buffer store ZSP, a code record store area CSB, and

for the initial addresses sia of the signalling information items sistored in the buffer store ZSP, a plurality of signalling informationstore areas SSB.

The information element store IES is, furthermore, structured on anoctet basis, i.e. a group OG of octets or bits is provided for each ofthe above-explained store areas KSB, TSB, CSB, SSB. Thus, in the case ofthe exemplary embodiment by way of example, there are provided for thelinking information item ki, the type information item ti and theinitial addresses csia, cia of the code record information item csi andthe signalling information items si in each case a group OG of octets,i.e. altogether seven groups OG1 . . . 7. As a result, an initialaddress specification can be given in the number of octets, startingfrom the first octet of a signalling message sm' in the buffer storeZSP'.

With the aid of a programmed enquiry routine ABR, the buffer-storedinformation items ti, csi, si of the individual information elements IE1. . . n can be retrieved selectively or multiply by the furtherprocessing routines and be further processed. This is effected by thetype store areas TSB being checked for the relevant type informationitem ti by the enquiry routine ABR in the auxiliary address store HASaccording to the information type to be selected and, after finding theinformation type to be selected, reading, i.e. enquiring, the assignedcode-record and signalling information item csi, si, from the bufferstore ZSP' with the aid of the initial addresses csia, sia, it beingpossible if there are a number of information elements IE1 . . . n ofthe same type with the aid of the linking information item ki to definethe first and last information element IE1 . . . n of the same type andenquire them in a corresponding sequence.

Furthermore, the information items ki, ti, csia, sia stored in theauxiliary address store HAS can be provided for the forming of asignalling message sm". This is the case in a communication device Kwhenever a received signalling message sm' is to be passed on inapproximately unchanged form, but also in modified form, to a furthercommunication device KE. Provided for the forming of such a signallingmessage sm" in a further buffer store ZSP" is the enquiry routine ABR,initialized by a formation routine BR--defined by dash-dotted lines. Theformation routine additionally has a message header routine MKR, withthe aid of which, for example, message header information items mkiretrieved by a further routine WR or the message header MK are insertedinto the signalling message sm" in the buffer store ZSP. With the aid ofthe enquiry routine ABR and the respective auxiliary address store HAS,the information items ti, csi, si stored in the buffer-stored signallingmessage sm' are inserted into the respective regions of the informationelements IE1 . . . n of the signalling message sm" to be formed in thefurther buffer store ZSP". It is indicated by the different number ofsignalling information items si in the respective information elementsIE1 . . . n that only those information contents of the signallinginformation items si for which initial addresses a are entered in theauxiliary address store HAS are inserted into the signalling message sm"to be formed.

In this forming of the signalling message sm", essentially the initialaddresses a stored in the auxiliary address store HAS are used to copythe information element-individual information items ti, csi, si storedin the buffer store ZSP' into a further buffer store ZSP", setup for thesignalling message sm" to be formed. If, however, there are noinformation items ki, ti, csia, sia stored in the auxiliary addressstore HAS, i.e. a signalling message sm" is being formed for the firsttime, the information element-specific information items ti, csi, si areformed with the aid of information element routines IER1' . . . n'provided for this and, subsequently, both combined to form a signallingmessage sm" in the buffer store ZSP" and the information items ti, ki,defining the information element type, and the initial addresses of theinformation element-specific information items csia, sia, stored in thebuffer store ZSP, are entered into a further auxiliary address storeHAS'.

After the forming or analyzing of a signalling message sm', sm", thebuffer store ZSP, setup in the main memory RAM in the communicationdevice K, and the auxiliary address store HAS are released for otheruse.

The invention is not limited to the particular details of the methoddepicted and other modifications and applications are contemplated.Certain other changes may be made in the above described method withoutdeparting from the true spirit and scope of the invention hereininvolved. It is intended, therefore, that the subject matter in theabove depiction shall be interpreted as illustrative and not in alimiting sense.

What is claimed:
 1. A process for forming and analyzing signallingmessages in a program-controlled communication device, the signallingmessages having a message header and information elements appendedthereto, defining an information element type and having informationelement-specific information items, comprising the steps of:setting up,for each signalling message to be analyzed or formed for a first time, abuffer store for storing a signalling message, and an auxiliary addressstore for storing buffer store addresses; defining and entering, on aninformation element basis into the auxiliary address store, using anaddress generation routine the information items that define arespective information element type and initial addresses of theinformation element-specific information items that are buffer-stored inthe buffer store; transmitting an indicative information item thatindicates the existence of an auxiliary address store to furtherprocessing routines of the communication device.
 2. The process asclaimed in claim 1, wherein the information item defining theinformation element type is represented by a type information item andthe information items defining the information element-specificinformation items are represented by signalling informationitems,wherein, the auxiliary address store has an information elementstore which is assigned to each information element wherein a linkinginformation item defining the linking of the information elements isentered into a linking store area of the information element store,wherein the type information item is entered into a type store area ofthe information element store, wherein the initial addresses of theoctet-oriented groups of signalling information items stored in thebuffer store are stored into signalling information store areas of theinformation element store.
 3. The process as claimed in claim 1,whereinan information element-specific information item is representedby a code record information item indicating the current message record,and wherein there is entered into a code record store area of therespective information element store the initial address of the coderecord information items stored in the buffer store.
 4. The process asclaimed in claim 1, wherein the linking information item is formed by aninformation item indicating a last information element of a same type orat least a following information element of a same type.
 5. The processas claimed in claim 1, wherein there are stored in a test memorystructure, for each type of signalling message and the informationelements contained therein, signalling protocol-conformal protocolinformation items according to a currently provided signalling protocol,wherein, following entry of the information items into the auxiliaryaddress store, the information items of the buffer-stored signallingmessage are compared on an information element basis with the enteredprotocol information items of the test store structure using a checkingroutine and the auxiliary address store, and error information items areentered into an error indication store if signalling messages do notconform to the protocol or are incomplete.
 6. The process as claimed inclaim 1, wherein the information items of the signalling message areretrieved by further processing routines using a retrieve routine andthe auxiliary address store.
 7. The process as claimed in claim 1,wherein, when forming signalling messages, further information elementroutines and the address generation routine are used to supplement thesignalling message stored in the buffer store by further informationelements and in the set-up auxiliary address store by furtherinformation items which are entered into information element stores. 8.The process as claimed in claim 1, wherein, for a setting up or clearingof a buffer store and an auxiliary address store, a setting-up andclearing routine is provided.
 9. The process as claimed in claim 1,wherein, using a message header routine, the message header informationitems, contained in the message header of a signalling message, and alsothe error information items are controlled.
 10. The process as claimedin claim 1, wherein the signalling messages and their informationelements are structured according to CCITT recommendations Q.931 andQ.93B.